Neural crest cells migrate extensively during development. This migration is spatially and temporally precise, and the cells eventually form such diverse derivatives as: pigment cells, sensory and autonomic ganglia, teeth and the cranial connective tissues. Changes in distribution and composition of the extracellular matrix and the presence or absence of cell associated proteins on the crest cells may be related to the onset of neural crest cell movement and to control the pattern and pathway of migration. There are a number of mutant mice strains which are deficient in neural crest cell migration and differentiation and express such abnormalities as loss of pigmentation, cranial-facial lesions and absence of sensory and autonomic ganglia. I plan to test the role of the extracellular matrix and cell surface proteins in the control of neural crest cell migration by 1) correlating these factors with normal crest morphogenetic events and 2) comparing changes in these factors with concomitant morphogenetic events in mutant mice.